PROJECT SUMMARY ? Exposure Core A robust exposure assessment is key to the success of any environmental epidemiology or toxicology project and determining exposure can be complex as people are exposed to multiple compounds through multiple exposure pathways. During the initial funding period, the Exposure Core has become a well-known hub on campus for seeking advice on the exposure related portion of study design and for developing new and helpful methods and facilities to further environmental health research. The Exposure Core has helped connect investigators with analytical laboratories that can help further their exposure characterization, assisted epidemiologists with robust exposure assessment design, and aided toxicologists to quantify exposures and relate them to a relevant benchmark or tissue level. For multi-chemical scenarios, The Core has helped ensure that laboratory exposures model real-world human exposure scenarios. The overarching goal of the Exposure Core is to provide comprehensive exposure study design and analysis expertise to improve the quality of studies that require exposure assessment for epidemiological studies and exposure environments for toxicological studies, and hence improve the quality of environmental health research conducted at UC Davis. Exposure Core laboratories include expertise in: 1) target and non-target analysis of organic compounds in environmental and biological samples, 2) time-integrated or time-window specific exposure concentrations, 3) compositional analysis of environmental samples to identify organic functionality via FTIR and mass spectrometry and elements and isotopes via XRF and ICPMS analysis, 4) design guidance for animal inhalation toxicology studies from a range of air pollutants and sources, 5) resources for helping environmental justice communities determine potential exposures, an exposure vivarium for traffic related airborne particles, and 5) a portable wildfire measurement system. Core members continue to expand the capabilities of their labs to meet these growing needs of center members. The core is increasing our capabilities in helping faculty working with community groups to evaluate compounds of concern and develop streamlined methods for evaluating community exposures. The Exposure Core has developed a program to provide seed funding to investigators for method development to build capabilities. The Exposure Core also provides both subsidies and seed funding for sample analysis in the core laboratories for center members. We provide advice on the study design through Specific Aims Reviews hosted by the Administrative Core, through Exposure Design Reviews for potential pilot applicants, and through meetings with investigators. By providing exposure assessment expertise to investigators as part of an integrated core, rather than via independent campus laboratories, we will be able to provide a much more robust, appropriate, and custom tailored exposure assessment through our synergies, interactions and collaborations.